rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5846/1:b..l rcu: (detected by 0, t=10502 jiffies, g=9925, q=412 ncpus=2) task:syz-executor state:R running task stack:20744 pid:5846 tgid:5846 ppid:5826 task_flags:0x400140 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x1b33/0x51f0 kernel/sched/core.c:6767 preempt_schedule_irq+0xfe/0x1c0 kernel/sched/core.c:7090 irqentry_exit+0x5e/0x90 kernel/entry/common.c:354 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:707 RIP: 0010:unwind_next_frame+0x19e/0x23b0 arch/x86/kernel/unwind_orc.c:-1 Code: 24 24 4d 8d 74 24 35 4c 89 f5 48 c1 ed 03 42 0f b6 44 2d 00 84 c0 0f 85 7d 1a 00 00 4d 0f be 26 48 8b 44 24 38 42 80 3c 28 00 <48> 8b 5c 24 10 74 08 48 89 df e8 83 c8 bc 00 4c 03 23 49 ff cc 4c RSP: 0000:ffffc90003de6c28 EFLAGS: 00000246 RAX: 1ffff920007bcdb5 RBX: 0000000000000000 RCX: ffff88807c48bc00 RDX: 0000000000000000 RSI: ffffffff8ca0e260 RDI: ffffffff8ca0e220 RBP: 1ffff920007bcdb2 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: dffffc0000000000 R14: ffffc90003de6d95 R15: ffffffff816d9bc8 __unwind_start+0x59a/0x740 arch/x86/kernel/unwind_orc.c:758 unwind_start arch/x86/include/asm/unwind.h:64 [inline] arch_stack_walk+0xe7/0x150 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0x11a/0x1d0 kernel/stacktrace.c:122 save_stack+0xfc/0x1f0 mm/page_owner.c:156 __set_page_owner+0x93/0x530 mm/page_owner.c:329 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1f4/0x240 mm/page_alloc.c:1718 prep_new_page mm/page_alloc.c:1726 [inline] get_page_from_freelist+0x360d/0x37b0 mm/page_alloc.c:3688 __alloc_frozen_pages_noprof+0x211/0x5b0 mm/page_alloc.c:4970 alloc_pages_mpol+0x339/0x690 mm/mempolicy.c:2301 folio_alloc_mpol_noprof mm/mempolicy.c:2320 [inline] vma_alloc_folio_noprof+0x12d/0x260 mm/mempolicy.c:2355 folio_prealloc+0x2e/0x170 mm/memory.c:-1 wp_page_copy mm/memory.c:3478 [inline] do_wp_page+0x14d7/0x5dc0 mm/memory.c:3939 handle_pte_fault+0xfaf/0x61c0 mm/memory.c:6013 __handle_mm_fault mm/memory.c:6140 [inline] handle_mm_fault+0x1030/0x1aa0 mm/memory.c:6309 do_user_addr_fault arch/x86/mm/fault.c:1337 [inline] handle_page_fault arch/x86/mm/fault.c:1480 [inline] exc_page_fault+0x45b/0x920 arch/x86/mm/fault.c:1538 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0033:0x7f1a35343e29 RSP: 002b:00007fffb01706b8 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f1a353849d3 RDX: 0000000000000007 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001 R10: 000055556b0ec7d0 R11: 0000000000000246 R12: 0000000000000007 R13: ffffffffffffffa8 R14: 0000000000000006 R15: 00007fffb0170850 rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g9925 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=1 timer-softirq=3254 rcu: rcu_preempt kthread starved for 10502 jiffies! g9925 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=1 rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior. rcu: RCU grace-period kthread stack dump: task:rcu_preempt state:I stack:26376 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x1b33/0x51f0 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0x163/0x360 kernel/sched/core.c:6860 schedule_timeout+0x15b/0x2b0 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x2e1/0x1340 kernel/rcu/tree.c:2046 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2248 kthread+0x7b7/0x940 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 5957 Comm: syz.1.9 Not tainted 6.15.0-rc3-syzkaller-00008-ga33b5a08cbbd #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:get_current kernel/locking/lockdep.c:5082 [inline] RIP: 0010:__lock_acquire+0xa/0xd80 kernel/locking/lockdep.c:5083 Code: 0a 00 00 00 5b e9 96 3f 00 00 5b c3 cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 55 41 57 41 56 41 55 41 54 53 <48> 83 ec 40 65 48 8b 2c 25 08 10 65 93 45 31 ed 83 3d 3f 80 c0 0e RSP: 0018:ffffc90000a08bc0 EFLAGS: 00000046 RAX: 0000000000000001 RBX: ffff8880b87276d8 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8880b87276d8 RBP: ffffffff93651020 R08: 0000000000000001 R09: 0000000000000001 R10: dffffc0000000000 R11: fffffbfff20bd76f R12: 0000000000000001 R13: 0000000000000000 R14: 0000000000000046 R15: 0000000000000000 FS: 00007fb4707476c0(0000) GS:ffff8881250cf000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000022000 CR3: 000000002e84c000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire+0x116/0x2f0 kernel/locking/lockdep.c:5866 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:119 [inline] _raw_spin_lock_irq+0xd3/0x120 kernel/locking/spinlock.c:170 __run_hrtimer kernel/time/hrtimer.c:1765 [inline] __hrtimer_run_queues+0x67b/0xd40 kernel/time/hrtimer.c:1825 hrtimer_interrupt+0x403/0xa40 kernel/time/hrtimer.c:1887 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline] __sysvec_apic_timer_interrupt+0x110/0x420 arch/x86/kernel/apic/apic.c:1055 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:finish_task_switch+0x1ea/0x870 kernel/sched/core.c:5250 Code: c9 50 e8 e9 2e 0d 00 48 83 c4 08 4c 89 f7 e8 ad 41 00 00 e9 de 04 00 00 4c 89 f7 e8 70 38 99 0a e8 4b 76 39 00 fb 48 8b 5d c0 <48> 8d bb 18 16 00 00 48 89 f8 48 c1 e8 03 49 be 00 00 00 00 00 fc RSP: 0018:ffffc900046bf548 EFLAGS: 00000286 RAX: 79893e5ac2577500 RBX: ffff888033501e00 RCX: ffffffff81caacec RDX: 0000000000000000 RSI: ffffffff8e635648 RDI: ffffffff8ca0e280 RBP: ffffc900046bf590 R08: ffffffff905ebb77 R09: 1ffffffff20bd76e R10: dffffc0000000000 R11: fffffbfff20bd76f R12: 1ffff110170e74f6 R13: dffffc0000000000 R14: ffff8880b8639980 R15: ffff8880b873a7b0 context_switch kernel/sched/core.c:5385 [inline] __schedule+0x1b3b/0x51f0 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0x163/0x360 kernel/sched/core.c:6860 schedule_timeout+0xb1/0x2b0 kernel/time/sleep_timeout.c:75 do_wait_for_common kernel/sched/completion.c:95 [inline] __wait_for_common kernel/sched/completion.c:116 [inline] wait_for_common kernel/sched/completion.c:127 [inline] wait_for_completion+0x32f/0x600 kernel/sched/completion.c:148 rdmsr_safe_on_cpu+0x199/0x360 arch/x86/lib/msr-smp.c:181 msr_read+0x1a7/0x270 arch/x86/kernel/msr.c:66 vfs_read+0x21f/0xb90 fs/read_write.c:568 ksys_read+0x19d/0x2d0 fs/read_write.c:713 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf3/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fb46f98e169 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fb470747038 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00007fb46fbb5fa0 RCX: 00007fb46f98e169 RDX: 0000000000018ff8 RSI: 0000200000019680 RDI: 0000000000000003 RBP: 00007fb46fa10a68 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fb46fbb5fa0 R15: 00007ffdf093a6b8